Nifedipine 20mg

Description

Therapeutic action

– Uterine relaxant

– Antihypertensive drug (calcium channel blocker)

Indications

– Threatened premature labour

– Hypertension

Presentation

– 20 mg prolonged-release tablet

Dosage

– Threatened premature labour(short-acting capsule) 10 mg by oral route, to be repeated every 15 minutes if uterine contractions persist (maximum 4 doses or 40 mg), then 20 mg by oral route every 6 hours

–Hypertension (prolonged-release tablets)

20 to 100 mg/day in 2 divided doses or 20 to 90 mg once daily depending on the preparation used

Duration

–Threatened premature labour: 48 hours

–Hypertension: lifetime treatment

Contra-indications, adverse effects, precautions

– Do not administer to patients with severe cardiac disease (recent myocardial infarction, unstable angina).

– Do not administer if systolic blood pressure is below 90 mmHg.

– May cause:

• headache, flushing, peripheral oedema (common adverse effects at the start of treatment);
• dizziness, hypotension, tachycardia, nausea, gingival hyperplasia, rash.

– Stop nifedipine if ischaemic chest pain occurs or existing pain increases shortly after starting treatment.

– Do not combine with magnesium sulphate, salbutamol IV, and calcium channel blockers.

– Monitor combination with cimetidine (additive hypotension), phenytoin (risk of phenytoin toxicity), rifampicin (efficacy of nifedipine diminished), itraconazole (increased risk of oedema), be